Earth drilling devices, in particular horizontal drilling devices, are used to introduce earth drill holes into the soil by trenchless construction for supply and waste lines, for example, or to replace already installed old lines without a trench. To introduce the earth drill hole, generally a drill string having drill string sections is used, wherein the drill string sections are connectable to each other.
The use of a slide that can be moved back and forth in a frame for advancing and/or retracting a drill string is known from EP 0 886 034 B1, for example. The slide has a seat for a drill string section such that the drill string section can be moved in the seat in the direction of a feed axis to create the earth drill hole. The drive acting on the drill string section can act on the drill string section in the seat in a rotational and/or translatory manner.
The drive for moving the slide in the frame can be moved by means of a rack, which is securely connected to the frame, and a hydraulic motor that has toothed wheel which is mounted on the slide. Furthermore, a cylinder packet consisting of adjacent cylinders can be used.
It is furthermore known from DE 20 64 862 to move a platform by means of cables and a pulley or rollers. The cable is placed over a rotatable roller which is borne by a holder on an end of the cantilever and is guided running along the cantilever about another roller which is returned along the cantilever by means of a holder that is held on a piston of a dual-acting hydraulic ram.
A disadvantage of the method known from the prior art is that the full release of power is not transmitted in small advances, which is the case in particular with cylinder packets consisting of a plurality of adjacent cylinders. Furthermore, the high cost is disadvantageous. Use in a trench is not optimum since the construction is too bulky, and/or a desired useful drill string length is not achieved.